Field of the Invention
The present invention relates to an endoscope objective optical system such as an endoscope objective optical system that is applicable to an endoscope apparatus used in fields such as a medical field and an industrial field.
Description of the Related Art
In an endoscope objective optical system, sometimes, for carrying out oblique observation, a visual-field direction converting member such as a prism is disposed in an optical system. Examples of such optical systems for oblique observation have been proposed (refer to Japanese Patent Application Laid-open Publication No. 2008-83316, Japanese Patent Application Laid-open Publication No. Hei 9-269450, Japanese Patent No. 3574484 Publication, Japanese Patent No. 4439184 Publication, Japanese Patent No. 3742484 Publication, Japanese Patent No. 558058 Publication, Japanese Patent No. 4274602 Publication, Japanese Patent Publication after Examination No. Sho 53-36787, Japanese Patent Application Laid-open Publication No. Sho 51-62053, and Japanese Patent Application Laid-open Publication No. Hei 7-294806 for example).